"New version available" should print upgrade instructions

[vfonic]

Hey!

I assume this might be the most appropriate repo to report this issue.

1. "New version available" should provide some action items:

> shopify version
Current Shopify CLI version: 3.20.1
|💡 Version 3.22.1 available!

What can I do with this information? I don't remember how installed Shopify CLI. There are several ways to install it and I don't want to remember. The tool should tell me or at least tell me how I can find out.

2. brew upgrade shopify-cli is not enough. I'd recommend adding brew update && brew upgrade shopify-cli

Irrelevant details why `brew update` is needed

I've disabled most of Homebrew functionality and pinned all installed formulas. I disagree with Homebrew's "always install the latest version" policy. I believe there's a reason why we don't do that anywhere else in software projects.

For example:

==> Upgrading shopify/shopify/shopify-cli
  3.20.1 -> 3.22.1 

==> Installing dependencies for shopify/shopify/shopify-cli: openssl@1.1 and node
==> Installing shopify/shopify/shopify-cli dependency: openssl@1.1
==> Pouring openssl@1.1--1.1.1s.monterey.bottle.tar.gz
🍺  /usr/local/Cellar/openssl@1.1/1.1.1s: 8,101 files, 18.5MB
==> Installing shopify/shopify/shopify-cli dependency: node
==> Pouring node--19.0.1.monterey.bottle.tar.gz
🍺  /usr/local/Cellar/node/19.0.1: 1,991 files, 50.9MB
==> Installing shopify/shopify/shopify-cli

Apparently Node v18 (LTS) is not enough for Homebrew so it installed Node v19 to upgrade Shopify CLI.